New memberUsername: Solomonman
Post Number: 1
I have a Westinghouse LTV-32W3HD that when I turn it on the power light on the side quickly turns to blue from orange/yellow, flashes a few times and then stays blue. There is no picture at all. The same thing happens whether the remote or power button on the side of the TV is used.
I have taken a few electronics course - college level - but they were entry 100/200 level and about 15 years ago. I have read a little on how to test LCD TVs but I am open to any suggestions on troubleshooting (really Open to Learn). I have the user manual and the Westinghouse service manual (no electronic schematic just block schematic), after looking closely on the webpage for it ..the disassembly/block schematic is found here;
I opened the unit up and started with the power supply looking for bad caps with a magnifying glass and everything looked good. There was a light discoloration around one electrical component on the AC side of the Power Supply which I believe is a Triac. I found a website that talked about testing Triacs by using a OHM meter. I did the test and it passed (I believe) from what they suggested. Not sure if the website or I was 100% correct on the endeavor. The printed number next to that electronic component (triac?) on the board was Q601.
I have the below power supply in this TV.
I tested the following Voltages on the Power Supply while plugged in; (According to what I can make out on the board)
Standby 5vdc, switched 5vdc, 12vdc, and 24vdc. All voltages tested as expected.
I inspected the main board and nothing looks out the ordinary, Capacitors look fine nothing looks burned, loose, or discolored.
There appears to be 3 LEDs spread around the main board. Two are close together (D44/D45) and the last one is D17. The D45 is not on. D17 and D44 are red and on when the TV is powered on.
I have the following main board;
Not knowing if the LEDs mean anything, I moved on to the Inverter board. The VBLs connections all read 24 volts. The BLON reads 5 Volts. I believe the I_PWM gave me a reading of .8 volts one time but to be honest my online reading only mentioned BLON and VBLs being important so I did not focus much on the I_PWM, E_PWM,SEL, and IL_SEL values. I can retest if needed. Can someone clarify what these (I_PWM, E_PWM,SEL, and IL_SEL) connections represent or could be doing.
I have the following Inverter Board;
I moved on to the Backlight output from the inverter board. I get nothing, tried another multi-meter to make sure, at the highest Volts AC the meters could handle. I backed the meters down... same result. I moved in a ways to the 4 Large Capacitors on the board they all read 24 volts. The two inboard fuses on the inverter board (I believe from memory were 4A/160V) were not blown.
So being inexperienced, I am not exactly sure how to test the Voltage coming in to what I believe are transformers. There is also a connector (CN11) above the Large "CMO" label (all the way to the one side of the board) that hosts 2 wires. I have no idea what it is or if it could be some other influence that could be affecting the Backlight output not to occur. I believe CN11 Connection wires goes under the display metal encasement. The wires are not as thick as the other wires. I do not get any voltage reading from them as well.
So in short I am trying to confirm if the Inverter Board is the problem or if I should dig further into the TV to check out the TCON Board. The TCON board I know is at least connected to the main board from what I can see currently in the disassembly process.
Could also someone confirm if, I know this may be a "duh" question, the TV has to be connected to a (cable, antenna, computer) input source to have the inverter board supply power to light the backlights.
Any help is greatly appreciated,